This invention relates to an internal combustion engine and more particularly to the lubricating system for such engines.
As is well known, internal combustion engines require a lubricating system for providing lubricant to their moving components. In addition to the lubricating function, the lubricant also generally serves the function of cooling the engine, at least partially. With at least four cycle engines, the lubricating system includes a lubricant reservoir that stores the lubricant, an oil pump, that pressurizes the stored lubricant and circulates it through suitable passages to the lubricated areas and a return to the reservoir. Normally an oil filter is provided through which the circulated oil is passed to entrap foreign articles and prevent them from reaching the lubricated surfaces. Often the oil filter is associated with a heat exchanger to aid the cooling operation.
Thus the lubricating system requires a number of components, a drive for the pump or pumps, a filter arrangement and the formation and provision of the requisite passages for the lubricant flow, return and passage through the filter. Since the filter normally involves a cartridge that requires servicing, access and ease of servicing is important.
Japanese published application Hei 6-299863 shows a typical type of prior art approach to this problem. As seen therein, the engine has a cylinder block in which cylinder bores are formed. A bulkhead formed separately from the cylinder block and secured to its lower face acts with the cylinder block to support a crankshaft. A separate oil pan is secured to the lower face of the bulkhead and an oil pump driven by the crankshaft is supported on the bulkhead and depends into the oil pan. In addition to this construction conventionally the engine is provided with a bracket protruding from the engine body for removably securing an oil filter. The oil filter communicates with the engine through oil passages formed in the cylinder block, the bulkhead, and the bracket. Thus resulting in a complicated arrangement having a number of connecting joints that require effective sealing.
Another example of this complicated arrangement is shown in U.S. Pat. No. 5,647,315. That arrangement also adds an oil cooler to the oil filter body further complicating the plumbing of the oil and coolant passages. Also the mounting arrangement for the filter element is somewhat complicated and bulky.
It is therefore a principal object of the invention, to provide an effective oil filter mounting and connecting arrangement that reduces the number of connecting joints and permits more latitude in the filter mounting. In addition another object is to simplify and make the oil filter mounting more compact without adversely affecting serviceability.